Door lock

ABSTRACT

A door lock has a latch and a bolt reciprocal between open and locked positions and a key-operated lock cylinder for reciprocating the bolt between these positions. A locking bolt may be depressed into a latch engaging position for holding the latch in the locked position, and a train of levers is interposed between the reciprocal bolt and the movable locking bolt for lifting the depressed locking bolt out of engagement with the latch in response to the key-operated rotation of the lock cylinder to permit opening of the latch.

United States Patent [191 Wasserfaller July 22, 1975 [5 DOOR LOCKPrimary ExaminerAlbert G. Craig, Jr. [76] Inventor: Georg Wasserfaller,5923 Post Agent Kelma" Landskron, Gratschach, Austria 22 Filed: June 27,1974 [57] ABSTRACT A door lock has a latch and a bolt reciprocal between[21] Appl' 483686 open and locked positions and a key-operated lock 30 AP D cylinder for reciprocating the bolt between these posi- Forelgnpphcatlfm nomy ata tions. A locking bolt may be depressed into a latchen- June 29, AUStI'la position for the latch in t o ed po 52 US. CL...70 111- 292 150 sition and a of levers interPOsed between the E Int ClE65) 5/9/00 reciprocal bolt and the movable locking bolt for lifting[58] Field 70/1 1 1 the depressed locking bolt out of engagement withthe I l I I I I latch in response to the key-operated rotation of the[56] References Cited lock cylinder to permit opening of the latch.

UNITED STATES PATENTS 7 Claims, 2 Drawing Figures 1,071,266 l0/l9l3Schwieger 70/1 ll 'I i 15 A 6 15 1 e c 1 1- ,1

he. '1 l l 10 I 16 11 II 21 z ,..J 37

za I f; F 22. L" 11'- za noon LOCK The present invention relates toimprovements in door locks, and more particularly to locks whichcomprise a latch reciprocal between an open and locked position. a boltreciprocal between an open and locked position, key-operable means forreciprocating the bolt between the locked and open position. and alocking mechanism including a locking bolt movable between a latchengaging position for holding the latch in the locked position and aposition wherein the locking bolt is disengaged from the latch forpermitting the latch to be reciprocated into the open position.

Door locks of this type have been used widely for the doors of hotelrooms, for instance, and a specific application thereof has beendisclosed in Austrian Pat. No. 297,869. In such locks, it is importantthat the door may be locked from the inside independently of the lockingby the locking mechanism of the depressable locking bolt.

It is the primary object of this invention to provide a lock which maybe opened from the outside by a key even if the door has been lockedfrom the inside by the locking mechanism, i.e. by depressing the lockingbolt to keep the latch in its locked position.

The above and other objects are accomplished in accordance with theinvention by providing lever means operably associated with thereciprocal bolt and the movably locking bolt for moving the locking boltinto the disengaged position in response to the key-operatedreciprocation of the bolt into the open position thereof. The lockingbolt is mounted for movement under pressure in a direction transverse tothe direction of reciprocation of the latch.

According to a preferred embodiment, an unlocking lever is mounted forpivoting in response to the keyoperated reciprocation of the reciprocalbolt and the unlocking lever has an end pressing against an end of thelocking bolt in response to the reciprocation, the unlocking lever endis preferably beveled.

Preferably, an intermediate lever is arranged for pivoting in responseto the key-operated reciprocation of the reciprocal bolt and theunlocking lever is arranged to be pivoted by pivoting of theintermediate lever to press the end of the unlocking lever against theend of the locking bolt. The intermediate lever has a lug for engagementwith recesses in the reciprocal bolt.

The above and other objects, advantages and features of the presentinvention will become more apparent from the following detaileddescription of a now preferred embodiment, taken in conjunction with theaccompanying drawing wherein FIG. 1 is a plan view of the door lockaccording to the preferred embodiment of this invention, with the coverplate removed to illustrate the lock mechanism, and

FIG. 2 is a partial section ofa detail of the lock along line Il-II ofFIG. 1.

Referring now to the drawing, the lock is housed in case 1conventionally comprised of bottom plate or apron 2, a cover plate (notshown) and side wall 3, the lock case being affixed to the door. Latch 4is mounted in the case, with its tail end 4a defining notch 5 whichreceives nose or catch 6 of locking member 7 which is rotatable by adoor knob (not shown) in the direction of arrow B in a manner to bedescribed hereinbelow. Latch 4 is guided for reciprocation in adirection transverse to the axis of rotation of the door knob and member7 by pin 8 engaging longitudinal slot 9 in latch portion 4a. A spring 10is mounted in the case and biases latch 4 counter to the direction ofarrow A, the illustrated spring being a spiral spring having one endaffixed to the bottom plate of the case and a free end engaged in arecess in the latch.

Locking mechanism 14 (more fully shown in FIG. 2) is threadedly mountedin bottom plate 2 and comprises locking bolt which may be pressedinwardly into the lock case. As shown, the locking mechanism comprises ahousing having an axial bore slidably receiving the bolt. A retainingball is held in an annular groove in the locking mechanism housing andis inwardly biased into resilient engagement a respective one of twoannular grooves in the periphery of'the bolt. Under spring pressureexerted upon the retaining ball, the locking bolt will be held in itstwo respective operating positions. the ball yielding under axialpressure upon the bolt but snapping into an aligned annular bolt groovewhen this pressure ceases.

When locking bolt 15 is depressed into case 1. its end 15a engages therear end of latch 4-so that the latch cannot be moved in the directionof arrow A against the bias of spring 10. Thus, catch 6 of lockingmember 7 is held in fixed position and prevents rotation of the lockingmember and the door knob in the direction of arrow B.

The lock also comprises bolt 11 having portion 12 extending into case 1and defining recesses 13 in the underside of bolt portion 12. The boltrecesses are arranged to cooperate with, and be engaged by, cam or dog34 of lock cylinder 35.

An unlocking lever 17 is mounted in case 1 for pivoting about fulcrum16, one end 18 of the lever being in engagement with locking bolt 15.Lever portion 19 which engages bolt end 15a is bevelled.

Intermediate lever 21 is mounted in case 1 between bolt 11 and unlockinglever 17, lever 21 being pivotal about fulcrum 20. Lever 21 hasextension 22 forming knee 36 with the lever, the outer end of leverextension 22 having a guide or camming surface 23. Except for the archedportion 24, intermediate lever 21 is mounted in a plane below the planeof bolt 11. The arched lever portion has lug 25 arranged to be engagedin recesses 26 in the upper side of bolt 11.

The above-described lock is operated in the following manner:

The door is securely locked when locking bolt 15 has been depressed.When it is desired to unlock the door, a key (not shown) is inserted inthe keyhole of lock cylinder 35 and the latter is rotated in thedirection of arrow E. This rotation causes cam 34 to enter and engagerearward recess 13 of bolt 11. At the same time, cam 34 will engagecamming surface 23 of lever 21 to lift the same into the position shownin broken lines and to pivot it in the direction of arrow D whilesliding bolt 11 inwardly in the direction of arrow F, lug 25 having beenlifted out of engagement with recess 26. The lifting and pivoting ofintermediate lever 21 will cause its knee 36 to move into engagementwith cam 37 of unlocking lever 17. This will pivot lever 17 aboutfulcrum 16 into the position shown in broken lines, causing beveled end19 at the opposite end 18 of the lever to press against inner end 15a oflocking bolt 15, thus pressing the bolt outwardly and disengaging itsend 15a from the rear end of latch 4. This frees the latch for guidedmovement in the direction of arrow A by rotation of the door knob in thedirection of arrow B. Bolt 11 having been opened by operation of thelock cylinder. latch 4 may now also be opened by operation of the doorknob. and the door may be opened.

What is claimed is: l. A door lock comprising. in combination: I. alatch reciprocal between an open and locked posltron. 2. a boltreciprocal between an open and locked position, 3. key operable meansfor reciprocating the bolt between the locked and open position. I 4. alocking mechanism including a locking bolt movable between a latchengaging position for holding the latch in the locked position and alatch disengaging position wherein the locking bolt is disengaged from alatch for permitting the latch to be reeiprocated into the openposition, and 5. means operably associated with the reciprocal bolt andthe movable locking bolt for moving the locking bolt into the disengagedposition in response to the key-operated reciprocation of the bolt intothe open position thereof. 2. The door lock of claim 1, wherein thelocking bolt is mounted for movement under pressure in a directiontransverse to the direction of reciprocation of the latch.

3. The door lock of claim 2, wherein the means operably associated withthe locking bolt comprises an unlocking lever mounted for pivoting inresponse to the key-operated reciprocation of the reciprocal bolt, theunlocking lever having an end pressing against an end of the lockingbolt in response to the reciprocation.

4. The door lock of claim 3, wherein the unlocking lever end is beveled5. The door lock of claim 2, wherein the means operably associated withthe reciprocal bolt comprises an intermediate lever. mounted between thereciprocal bolt and the unlocking lever. the intermediate lever beingarranged for pivoting in response to the keyop'erated reciprocation ofthe reciprocal bolt and the unlocking lever being arranged to be pivotedby pivoting of the intermediate lever to press the end of the unlockinglever against the end of the locking bolt.

6. The door lock of claim 5, wherein the keyoperable means comprises alock cylinder and a cam movable by the lock cylinder into a recess inthe reciprocal bolt for reciprocation thereof.

7. The door lock of claim 5, wherein the intermediate lever has a lugfor engagement with recesses in the reciprocal bolt.

1. A door lock comprising, in combination:
 1. A latch reciprocal between an open and locked position,
 2. a bolt reciprocal between an open and locked position,
 3. key-operable means for reciprocating the bolt between the locked and open position,
 4. a locking mechanism including a locking bolt movable between a latch engaging position for holding the latch in the locked position and a latch disengaging position wherein the locking bolt is disengaged from a latch for permitting the latch to be reciprocated into the open position, and
 5. means operably associated with the reciprocal bolt and the movable locking bolt for moving the locking bolt into the disengaged position in response to the key-operated reciprocation of the bolt into the open position thereof.
 2. a bolt reciprocal between an open and locked position,
 2. The door lock of claim 1, wherein the locking bolt is mounted for movement under pressure in a direction transverse to the direction of reciprocation of the latch.
 3. The door lock of claim 2, wherein the means operably associated with the locking bolt comprises an unlocking lever mounted for pivoting in response to the key-operated reciprocation of the reciprocal bolt, the unlocking lever having an end pressing against an end of the locking bolt in response to the reciprocation.
 3. key-operable means for reciprocating the bolt between the locked and open position,
 4. a locking mechanism including a locking bolt movable between a latch engaging position for holding the latch in the locked position and a latch disengaging position wherein the locking bolt is disengaged from a latch for permitting the latch to be reciprocated into the open position, and
 4. The door lock of claim 3, wherein the unlocking lever end is beveled.
 5. The door lock of claim 2, wherein the means operably associated with the reciprocal bolt comprises an intermediate lever mounted between the reciprocal bolt and the unlocking lever, the intermediate lever being arranged for pivoting in response to the key-operated reciprocation of the reciprocal bolt and the unlocking lever being arranged to be pivoted by pivoting of the intermediate lever to press the end of the unlocking lever against the end of the locking bolt.
 5. means operably associated with the reciprocal bolt and the movable locking bolt for moving the locking bolt into the disengaged position in response to the key-operated reciprocation of the bolt into the open position thereof.
 6. The door lock of claim 5, wherein the key-operable means comprises a lock cylinder and a cam movable by the lock cylinder into a recess in the reciprocal bolt for reciprocation thereof.
 7. The door lock of claim 5, wherein the intermediate lever has a lug for engagement with recesses in the reciprocal bolt. 